The above people are wrong. I have bought the upgrade pack, and every single time that I have upgraded to 1.1.3/1.1.4 my upgrade pack comes straight back. So if you go to jailbroken 1.1.2, then use the Dev Team Soft Upgrade, when you sync with iTunes your upgrade pack will get synced straight to it.

But before you go and do that, have you tried using ZiPhone to jailbreak 1.1.4?

The above people are wrong. I have bought the upgrade pack, and every single time that I have upgraded to 1.1.3/1.1.4 my upgrade pack comes straight back. So if you go to jailbroken 1.1.2, then use the Dev Team Soft Upgrade, when you sync with iTunes your upgrade pack will get synced straight to it.

But before you go and do that, have you tried using ZiPhone to jailbreak 1.1.4?